We May Absorb 60 Dark Matter Particles An Hour

WIMPs (Weakly Interacting Massive Particles) are a theoretical class of matter that are suspected of being the elusive “dark matter” that presumably constitutes 80 per cent of the universe. A new study by the University of Michigan suggests that these phantom particles might strike our bodies once every minute.

Katherine Freese, a professor with the Michigan Center for Theoretical Physics at the University of Michigan coordinated with Christopher Savage, a postdoctoral researcher with the Oskar Klein Centre at Stockholm University in Sweden for this study.

Theoretical physicists believe that WIMPs, which rarely interact with normal matter but commonly interact with each other, pass through the Earth by the billions every second. Since they don’t often interact with normal matter, the chances of one of these particles striking a nuclei in your body were thought to be exceedingly low — like, once in a lifetime. However this new study suggests that these interactions occurs pretty much constantly.

Freese and Savage applied existing models of various WIMP masses and prevalence, then estimated how often these particles would interact with the nuclei most commonly found in people — hydrogen and oxygen. Turns out, both hydrogen and oxygen are struck more often by WIMPs than many other elements and, since we’re mostly water, we’re veritable WIMP magnets.

So, what happens when a WIMP hits an nucleus in, say, your liver? Despite the fact that these particles are theoretically many times larger than the average nucleus, its weakly interacting nature precludes it from doing much harm. There is a chance that the collision in your liver, “could cause a mutation that would be bad for you,” Freese said. “But the odds of it happening are really low.” I, for one, am reassured that the chances of a particle we’re not even are really sure exists has a relatively low chance of giving you cancer. [ArXiv via NatGeo]